Method of making yarn



Aug.-22, 1944. E, FRANZ 2,356,574

` METHOD OF MAKING YARN A Filed Deo. 31, 1937 INVENTOR Ehrhart F'anz mi; .A i

TORNEY Patented ug. 22, 1944 METHOD OF MAKING YARN Elu-hart Franz, Leipzig, Germany; vested in the Alien Property Custodian Application December 31, 1937, Serial No. 182,910

Germany January 27, 1937 3 claims. v(ci 19-146) This inv'entionl concerns a manufacture of yarn f/rom staple bre, or from such fibre in mixture with other fibre. Staple fibre, i. e., fibre cut from rayon lament by way of contrast to -natural textile fibre, consists in the present art of threads lcut fairly uniformly to a definite length corresponding to `thatof natural cotton or wool bre. The filament is thus, e. g., afterhaving been-exuded from the spinning bath, cut and loosened, e. g., it is floated in water and upset by obstacles opposing the free flow of the pieces in the water. The loosened staple Y fibre is then treated on carding machines andso forth, similarly to natural bres, and finally spun into yarn. Attempts to work the staple fibre directly,` i. e., without loosening and combing, have not met with success. But it has always been considered of importance-that the filament be as uniform as possible in size, and also as to the length of the staple fibre.V

In accordance with the instant invention, a yarn, which is greatly improved in many respects is obtained when we do not reduce vthe filament to staple of uniform. size and length. But the filament is cut into pieces of different lengths, the choice in the mixtureof Varying lengths depending upon the particular nature and prior treatments of the artificial filament. The best possible ratios as to lengths and quantities Vof 4different lengths are, preferably and most readily determined in an empirical way, by 4systematically preparing mixtures of varying ratios of `fact crossbred wool cannot be successfully mixed with rayon, unless there isa scheduled mixing of fibre of different size.

Particular advantages will resultfwhen a xed mixing schedule is observed, which can be readilyascertainedby test, and in which the mixing of the fibre is rationed in respect tothe size as Well as concerning the length of the filament; generally speaking, it is advisable to uselonger pieces of ner, and shorter pieces of heavier bre or filament.

'I'he maximum of using greater lengths of thinner bre is also known in the" conversion of natural fibre. It was the natural outcome of the recognition, that uniformity in length and size must be observed in order to obtain a yarn of greater strength-aside from a careful consideration of the convolutions per unit length in and proportions, and by a comparison of the resultant yarns in respect to their Y mechanical 1 characteristics. e

YIt is also of advantage to use filament varying in neness, e. g., to make filaments of different neness or size; and then again to determine empirically the best' possible ratio of mixing. A careful analysis of commercial rayon has been carried out in this connection and has elicited, that Ithere are considerable variations and uctuations as to the size of lament. But the arbitrarin'ess with which such variationsl and nuctuations occur, indicates that they are caused by accidental variations in the clear opening of the nozzle through which the filament is exuded; they cannot be attributed to a predetermined and planned schedule of variations in size. On the other hand my research has also shown, that a predetermined coordination as to fineness, e. g., a planned mixing in a fixed proportion of filament assorted a's tov size, isextremely usefultwisting and doubling. Thus diagramsevaluating the length and fneness or size of the bre have come into general use in connection rwith natural fibre. But it has not been known before to assoit the rayon fibre in this manner, to mix assorted libres and thus to obtain superior results. This must evidently be attributed to a lack of analogy-according to which We cannot, for instance, compare the scaleless rayon with a well scaled and crimped wool; fixed rules do not apply to one as Well as the other though artificial crimping of rayon ,fibre confers more wool-like properties upon the rayon.

lAssorted fibre may be dosed in the empirically evaluated preferred ratios. of lmixtures in various ways. Thus the endless rayon filament is not cut in uniform-length as before, but the cut is arranged so that We immediately have a mixture i of varying lengths of bre, i. e., they vary in for rug and carpet for instance. As a matter-66 accordance with the predeterminedly preferred ratios of length. Variations ofl size may of course be simultaneously obtained by predetermined diierentiations in the clear opening -of` different nozzles.

We may modify the operation by'cutting from the endless filament bundles of different length, each bundle containing staple of like length, and may then mix with each other bundles, which differ from each other infrespect to length.

A predetermined assorting in respect to length as well as to size maybe brought about, by providing shorter bundles of ner filament, and longer bundles of heavier filament, the staple of each bundle being, of course, uniform'in length.

Then the various bundles are.mixed with eachI other in accordance with,v the predetermined schedule.

terial mentioned hereinabove.

In order to eiect a difference in length between the various nlamentary pieces of a bundle, we may cut at an angle and/or along a curved path, such lcuts alternating with cuts in a normal, transverse direction, or with cuts conversely slanted or curved. If'in successive cuts the cutl tings 'means is for instance oppositely slanted,

these cuts may be reversed in respect to each other in mirror fashion.v

-'It should be mentioned that such a predeterminedly mixed material may even go immediately into the combing process, i. e.,fthe steps uof loosening and carding might be dispensed with, and

considerable losses which are normally entailed in these steps of procedure are thus eliminated. 'I-'he same applies to the artincially crimped ma- The advantages obtained by use of the instant invention and its procedure will be better understood from 'the following comparison, which is however to be 4interpreted as an illustration rather than in limitation.

The chart below lists to the left the length and size of-each staple nbre used, their size being given in denier and their length in millimeter. To the right we have lots with different mixtures of these nbres,.the percentages of the various nbreI, II or III, fmixed together in each lot being tabulated under the heading of the lot (A, B, C 01 D).

Staple nbre Fibre mixtures Denier' Length Lot A Lot B Los oj Lot D Millimeter.: Per cent Per cent Per cmi Per cent I 2.75 100 100 75 33 66 II 3. 75 1m 33 l III..- 6. 00 150 25 34 34 Yarns A, B, C and D were worked upy in the.

ordinary worsted process. Even initially, before the spinning operation, lots B and C proved 'vastly superior to lot A, and this was more outspoken in respect to lot C than lot B. In the spinning process lot A again was greatly inferior, but in this instance lotC was slightly better than lot B. The material was spun at 3300 R. P. M. with 6.03 twist per centimeter, 52 meters of yarn per grain. The mechanical test then showed the following comparison:

A C D Less than two-thirds ofthe average strength cent.. 10.0 4.3 7.=2 Breaking length .km.. 6. d. 82 7. 45 Breaking strength grams.. 112. 2 132. 5 144. 9 'Elongation per cen 6.2 6. 2 7.0

Unevenness.-. .do. 20.43 14. 82 18.93 Breaks .do 2.96 0.85 1. 72 Nubs per gram combed 64 26 34 For a carpet-material a mixture of yarns 25-35 denier with yarn 3-5 "denier proved particularly suitable for spinning.

The mixtures of staple nbre observed in yarn of the prior art, and mixtures which have been empirically proven toA be superior, are tabulated in the chart of the accompanying drawing, in

whichv Fig. 1 Vshows analyses of various yarns, the

thicknesses being plotted inthe direction of the 4shown the best properties.

abscissa, and the percentage in the direction of the ordinate.

Fig. 2 represents a chart of yarns where the length is plotted in the direction of the abscissa against the percentage in the direction of the ordinate.

In Fig. 1 the curveE, which has been executed as a dash line, shows an analysis as to size of a yarn made from staple fibre in the prior art, and showing denier 7:22 to 28p.

VCurve F, which is executed in a dotted line, shows an improved mixture of this invention. It was obtained by mixing commercial sizes averaging 3.75; '7; 11; 22p.

The solid curve G of Fig. 1`illustratesuan empirically evolved standard for a yarn, which has The mixture "of the yarn of curve G comprises the lsame sizes denier, as were used in connection with the curve F.

The curve H of the second chart shownv in Fig. 2 tabulates the lengths of staple nbre found in a yarn of the prior art, which had been assembled from commercial staple fibre length ranging between mm. and 120 mm.

Varying lengths of staple nbre ranging from 80 mm. to 150 mm. yielded a yarn of best qualities when mixed as shown in the solid curve J of Fig. 2.

The square nelds of the curves show, of course, averages inwhich, for instance,35 mm. and 45 mm. lengths are combined to an average of 40' mm. or to 115A mm2 are combined into the group of mm.

Having thus described my invention in detail, yet I'do not wish to be limited thereby, except as the state oi the art and the appended claims may require, for it is obvious that various modincations and changes may be made in the form of embodiment of my invention, without departing from the spirit and scope thereof.

` WhatI claim is:

1. The method of making yarn of staple nbers comprising cutting a bundle of continuous extruded artificial nlaments successively along transverse lines, each cut being inclined relative to adjacent cuts to form bunches of .nbers having an empirically predetermined non-uniformity of nber lengths, mixing and combing said bunches ofnbers, and then forming said nbers of predetermined non-uniform length into a yarn.

2. The method of making yarn of staple nberscomprising cutting a bundle of continuous extruded rayon nlaments successively along transverse lines, each cut being at an angle to adjacent cuts to form bunches of staple nbers having an empirically predetermined non-uniformity of nber lengths, mixing and combing said bunches of nbers, and then forming said nbers of pre determined non-uniform length into a yarn.

3. The method of making yarn of staple nbers comprising cutting a bundle of continuous extruded artincial nlaments along transverse lines, alternating said cuts with a second set of transverse curved cuts to form bunches of staple nbers' having an empirically predetermined'non-uniformity of fiber lengths, mixing and combing said bunches of nbers, and then forming said nbers of predetermined non-uniform length into 

